Automatic three-dimensional pattern controlled milling machine



Jan. 26, 1937. B. sAssEN 2,068,890

AUTOMATIC THREE-DIMENSIONAL PATTERN CONTROLLED MILLING MACHINE Filed July 1o, 1935 4 sheets'fsheet 1 I ATTORNEY.

ED MILLING MACHINE B. SASSEN Jan. 26, 1937.

UTOMATIC THREE-DIMENSIONAL PATTERN CONTROLL Filed July lO, 1935 4 Sheets-Sheet 2 Jan. 26, 1937. B. SASSEN 2,068,890

' AUTOMATIC THREE-DIMENSIONAL,PATTERN CONTROLLED MILLING MACHINE Filed July 10, 1935 4 sheetssheet 5 zqf . 7 /6/ INVENTOR.

www 54552 lf2/L l '\.AJ l) 1 Izq 7 ATTORNEY.

Jan. ze, 1937. B. sAss-:N 2,068,890

l AUTOMATIC THREE-DIMENSIOIAL PATTERN CONTROLLED MILLING MACHINE Filed July l0, 1935 4 Sheets-Sheet 4v A BY 65e/WMM,

ATTORNEY.

Patented Jan. v26, l1.937

PATENT OFFICE AUTOMATIC THREE-DIMENSIONAL PAT- TERN CONTROLLED MILLING MACHINE Bernard' Sassen, Cincinnati, 0hio, assignor to The Cincinnati Milling Machine Co., Cincinnati, Ohio, a corporation of Ohio Application July 10, 1935, Serial No. 30,745

24 Claims.

This invention relates to improvements in duplicating machines of the type wherein a tracer moving with light pressure 'over a pattern, which may be of relatively soft material, controls an amplied or relatively large force which conrttrols the positioning of a cutter whereby the cuter may form in a. work piece of relatively hard material a duplicate of the pattern.

One of the objects of this vinvention is to produce a lmechanism whereby a conventional milling machine may be utilized for automatic duplicating purposes.

Another object vof this invention is'to provide auniversal pattern controlled mechanism which is operable to produce three dimensional objects in a single cycle of the machine.

A further object of this invention is to provide in combination with a mechanism for rotating a work piece with respect to a tool which ismovable toward and from the axis of rotation of the work to vary the diameter thereof, of means for maintaining the cutting rate substantially constant regardless of changes in the diameter of the work, and also of providing means rendering it possible to vary the cutting rate.

An additional object of this invention is to provide an improved andy simplified hydraulic control circuit for controlling the direction of relative movement between a cutter and work piece automatically and under control of a relatively movable tracer and pattern.

Other objects and advantages of thepresent.

invention should be readily apparent by reference to the fcllowing'specication, considered in conjunction with the accompanying drawings forming a part thereof and it isto be understood that any modifications may be made in the exact structural details there shown and described, Within the scope of the appended claims, without departing from or exceeding the spirit of the invention.

Refe r^1ng to the drawings in `which like ref-- erenc numerals indicate like or simi1arparts:'

Figure 1 is a front elevation of a machine tool embodying the principles of this invention. *Figure 2 is a side-view of the machine shown in Figure 1.

Figure 3 is a detailed sectional `view tken onl the line 3--3 of Figurefl.

Figure 4 is a detail view in'plan of the cutting vrate control member, as viewed from line II--4 of Figure 2.

Figure 5 is an enlarged detail view in elevation showing the shape of the cutting rate determinator.

of the machine.

Figure 6 is an end view of the meniber shown in Figure 5 as viewed along the line 6-6 of that ligure. f

Figure 7 is a detail view of the mechanism for connecting and disconnecting the table for simultaneous movement in'predetermined relation with the rotation of the work.

Figure 8 is an enlarged section of the cutting rate determinator -as viewed from line 8,-8 of Figure 3. l0 Figure 9 is a detailed-view ofthe table reversing mechanism. Figure 10 is a diagrammatic view of the entire f transmission'and hydraulic control mechanism 1'6 For exemplary purposes, a conventional milling machine structure is shown in Figuresl 1 and 2 of the drawings and comprises chiefly a column I0 havingA vertical guide ways I I formed upon one face thereof, upon whicha knee I2 is vertically 20 slideable. The knee has horizontal guide ways I3 for receiving and guiding a saddle I4 which .is adjustable toward and from the' face of the l'ustrated diagrammaticallyin Figure 10 of the 35 drawings. The form illustrated vhas a common prime mover ZI which, as shown in Figure'2, may be mountedin the rear of the column I0. 1 The drive pulley 22` of this motor may beconnected by a suitable power transmitting, band'23 to a 40 Vdrive pulley 24 `flxed to the end of the main drive shaft 25..v ,I

A suitable form of I friction clutch -26 may be utilized. to .connect the main drive shaft to the f.

variable speed transmission 2'I which` terminates 45 t in an output shaft 28 havinga bevel gear 29 in-,. termeshing with a bevel gear 30 which is fixed i with the column and has a splined connectionv with the spindle I9 whereby thespindle may be moved` vertically with the carrier I8. Without breaking the driving connection thereto. The variable speed transmission consists of a primary shaft 3| upon which is splined two shiftable gear couplets 32 and 33, the formercomprising gears .34 and '35 shiftablerespectively into 55 mesh with gears 36 and 31 xed with the second-l ary shaft 38. The other couplet comprises gears 39 and 40 shiftable into mesh with gears 4| and 4,2 also fixed with shaft 38 whereby the latter may be driven at anyone of four different speeds.

A tertiary shaft 43 carries a shiftable couplet 44 comprising gears 45 and 48 shiftable respectively into mesh with gears 4I and 41 carried by shaft 38 whereby the shaft 43 may be driven at any one of eight different speeds. The shaft 43 also has a shiftable gear 48 which may be directly meshed with gear 49 for rotating the back gear shaft 50 ln one direction, or indirectly connected thereto through the intermediate idler gears and 52 for rotating the shaft 50 in an opposite direction.

This mechanism constitutes a reverser for the tool spindle.

The back gear shaft 50 has the shiftable couplet 53 splined thereon comprising gears 54 and` 55 shiftable into engagement with gears 56 and 51 respectively, which gears have integral therewith,

the gear 58 intermeshing with gear 59 which is fixed with shaft 28. By means of this mechanism it will be seen that the cutter spindle may be rotated at any one of sixteen different speeds and in either a clockwise or counterclockwise direction.

The transmission for shifting the table, saddle and knee consists of a primary shaft 60 which has a gear 6I secured thereto and directly meshing with gear 62 integral with shaft 25, whereby the shaft 60 is continuously rotated during operation of the prime mover 2|. This primary shaft actuates a rapid traverse transmission and a variable feed transmission, and has a rst gear 83 which is connected by a gear train 64 to the final output gear 65 of the variable speed transmission.

The shaft 60 has a gear 66 which drives the variable feedtransmission which may consist of a shaft 61 havinga gear 88 intermeshing with gear 66, and a shiftable gear couplet 69, comprising gears 10 and 1I shiftable into mesh respectively with gears 12 and 13, for causing rotation of shaft 14 at different rates. The shaft 14 also has gears and 16 fixed thereto which'are adapted to be interengaged by gears 11 and 18 of a second shiftable gear couplet splined on shaft 19, whereby the latter may be rotated at a plurality of different rates. The shaft 19 has gear 80 fixed therewithv which drives the final output gear 8| of the feed transmission, this gear being co-axial with gear 85, and both are supported on the final output shaft 82. The gears 65 and 8| may be mounted for free rotation and each provided with means lfor interconnection with the shiftable clutch member 83 which is splined to the shaft 82 whereby when the clutch member is shifted in one direction the shaft 82 will be rotated at a rapid traverse rate, and when the clutch is shifted *1in an opposite direction the variable feed transmission will be connected for rotation of 'shaft 82.

'I'he shaft 82 may be journaled yin the column of the machine and connected through bevel gearing 84 and vertical4 spline shaft 85. to gear 86 carried by the knee I2, whereby as the knee moves up and down, the gear 86 may also move relative to'shaft 85 without breaking the driving connection therebetween. The gear 86 drives, through spur gear 81 and bevel gearing 88, the shaft 89 which is interconnected by spur gearing 90 to the spline shaft 9|. This shaft may extend parallel 'td'the direction of movement of the saddle, and bevel gearing y92 may be supported in the saddle for movement therewith while maintaining a driving connection with the shaft 9|. This bevel gearing serves to drive the reversing mechanism, indicated generally by the reference numeral 93, which serves to change the direction of movement of the table. 'I'his reversing mechanism comprises a bevel gear 94 which rotates in opposite directions a pair of bevel gears 95 and 96 having clutch teeth on opposing faces thereof, which are adapted to be selectively interengaged with the supported for free rotation on a shaft |01 and are selectively connected thereto by an intermediate shiftable clutch member |08 which serves to change the direction of movement of the saddle to which the shaft |01 is connected.

The-gears |03 and |06 also intermesh with gears |09 and I I0 mounted for free rotation in the knee drive shaft I I I. These gears are selectively connectible to the shaft by an intermediate shiftable clutch member I I2. Suitable manual control 'means may be provided for shifting the clutches |08 and I|2 for changing the direction of movement of the saddle or knee, and they are also movable to an intermediate or central position for stopping the movement of the respective supports.

The table reversing control clutch 91 may be manually or automatically shifted by means of the mechanism shown in Figure 9 comprising a shifter fork |I3, which is pivotally mounted at I I4 and operatively connected to the manual control lever I I5. This lever may be utilized to effect engagement of the clutch with either of the bevel gears 95 or 98.

Automatic disengagement maybe effected by control dogs I6 and I I1 which may be selectively positioned in a conventional manner in the T slot I|8 formed in the edge of the table, 'and these dogs may cooperate with wings [I9 and I- formed integrally with the handle II5 for power rotating the same to la clutch disengaged position.

' rod |22 which is slideably supported in the column and continuously urged in one direction by a spring |23 to normally couple the feed transmission for actuation of the table. "The shifter rod |22 has rack teeth |24 interengaged by a pinion secured to a rotatable shaft |26 which has a second pinion |21 on the lower end thereof interengaging with rack teeth formed on the slideable member |28. This interconnecting member has rack teeth |29 formed thereon in 90 phase relation to the rst se't of rack teeth for interengagement with a pinion held for rotation in the column and integral with a shaft |3I. This shaft extends parallel to the direction of movement of saddle I4 and has a splinedtelescoping connection with an oscillatable tube |32 which is xed for rotation in the saddle, and therefore movable with respect to the shaft I3I. The end 1 of the tubular shaft |32 has a manually operable handle |33 which, when actuated, will compress the spring |23 and effect engagement of the feed-rapid traverse selector clutch 83 with the rapid traverse-gear 65. By means of this mechanism itis possible for the operator, when the table control clutch 91 is in one of itspower transmitting positions, to procure rapid traverse movement of the table.

The clutch 26, which serves to connect the prime mover with the spindle transmission to start and stop the spindle, may be operatively connected to the control lever |34 pivotally mounted at |35, as shown in Figure 2, by a link |36 which is connected at one end to a crank |31 'l `integral with the lever |34 and a crank |38 integral with the clutch shifter |39, the latter being pivotally mounted for rotation about the pin |40.

Thel foregoing transmission provides means for starting and stopping the cutter spindle, as well as for rotating it at different rates, together with means for traversing the table at variable feed rates, or at a rapid traverse rate, and control means for selecting either a feed rate or a rapid traverse rate, as well as reversing means for determining the direction of movement of the table.

Detachable means have been provided where, by this machine may be utilized for performing pattern controlled fmachining operations and comprises, in general, a tracer head indicated generally by the reference numeral |4|, Figure 1, which may be detachably connected to the spindle carrier I8 for movement therewith, and a fixture indicated generally by the reference numeral |42 which may be detachably connected to the table for rotatably supporting and driving a pattern |43 and a work piece |44. Power operable'means have also been provided under the control of the tracer for causing a relative spiral movement between the work-piece and the tool, together with means for moving the carrier |8 toward and from the work piece in accordance with the profile of the pattern whereby a three-dimensional object may be produced, which is inexact conformity with a three-dimensional pattern.

The spiral movement is effected by an hy-4 draulic motor |45 which is contained in the housing |46 of the xture and operatively connected through a worm |41 andworm gear |48 to a drive shaft |49 which -is journaledv in the housing, and has means at opposite ends for driving a pattern supporting arbor |50 and a Y work blank supporting arbor v|5|. If desirable, dead centers |52 and |53 may be mounted on the table for supporting the free end of these arbors The -mechanism described lso far imparts the rotary component 'of the spiral movement. The means for effecting the longitudinal component of this movement will now be described.

The shaft |49 drives a gear |54 secured thereto in mesh with spur gear |55 attached to the end of a shaft |56 which extends to the end of the housing |46., As shown in Figure 7, the end of shaft |56 has one member|51 of a friction disc clutch keyed thereto and theoth'er member |58, which'is not keyed to the shaft |56, has integral therewith a lpinion gear |59. A nut |60 threadedon the end of shaft |56 acts through the spring plate |6| to vary the amount of friction between the friction disc plates, and thereby the point at which slippage will take -place between the shaft 56 and the gear |59. The purpose of this will be explained more fully later.

'I'he gear |69-is adapted to be interengaged b a shiftable gear |62 slideably mounted on a shaft |63 which is supported in the fixture |42. The

gear |82 has a hub |64 to which may be secured` a detachable change gear |65 adapted to intermesh with a change gear |66 detachably mounted on the end of the table lead screw 98. ,Since the gears |65 and |62 are integral they may be simultaneously shifted by a shifter fork |61 which engages the periphery of gear |62 to break the driving connection between the shaft |56 and the lead screw.- The shifter forkmay be actuated by the manually operable handle |68 and a suitable spring pressed detent |69 provided for holding the parts in either position.

From the foregoing it will now be seen that the hydraulic motor |45 not only rotates the work and pattern but is also. connected for effecting longitudinal movement of the table in predetermined timed relation to the rate of rotation wherebya uniform spiral feeding movement between the tool and work may be effected.

After the cutting operation has been completed the gear unit |62 may be shifted to disconnect the table lead screw from the lhydraulic motor |45 and the clutch 91 engaged for power actuation of the table from the prime mover 2|, and

of a servomotor coupled for control by the tracer |10 which engages the pattern |43. The servomotorcomprises a cylinder |1| having a containedpiston |12 which is operatively conn ected by the piston rod |13 to the carrier I8. The piston rod has a pair of axially extending channels ,|14 and |15formed therein, lthe end of channel |15 terminating in the space above piston |12, andthe channel |14 being connected by a cross vbore |16 to the space below the piston |12. y

The channels |14 and |15 are connected by pipes |11 and |18 to ports A|19 and |80 of the tracer control valve, indicated generally by the reference numeral 8|. This valve has a pressure port |82 'to which fluid is supplied through a pipe |83 by a pump |84. 'I'he pump has an intake pipe |85 through which fluid is withdrawn and has'a pendulum |88 which is normally actuated by a spring |89 in a direction to increase the volumetric output of the pump. Since the pressure port |82 is closed a greater part of the time by the spool |90,' automatic means have been provided for preventing excessive pressures inthe channel |83 and comprise a cylinder |9| which is connected by a branch |92 to the pipe |83. The cylinder |9| has a piston |93 which is operatively connected to the pendulum |88 in such a manner that the pressure in the cylinder acts in a direction against the action of the 4spring |89 to reduce the delivery ofthe pump.

By Calibrating the spring |89 it .is possible to maintain a predetermined pressure in the channel, |83, and the spring is so calibrated in this case that 'the pressure is sufficiently high' to insure instant and accurate movement of `the carrier|8.j,

lThe spool |90 isintegral with the tracer valve plunger A|94 which is supported by the antifriction ball |95mounted in the end of the tracerv arm |96. This tracer arm has a spherical portion |91 by which it is supported for universal movement in the tracer housing |98. The tracer |10 is detachably connected to the end of the tracer arm |96.

When the tracer is in contact with the pattern the tracer arm |96 and the valve plunger |94 are elevated a sufiicient amount so that the spool |90 is central of port |82 and thereby no fluid flows from the port to pipes |11 and |18. But should the tracer engage an eminence or a de. pression on the pattern the spool |90 will be moved upward or downward as the case may be and thereby couple port |82 toeither port |19 or port |80. Simultaneous with this connection the annular grooves |99 or 200 formed on oppo- 202 respectively whereby the iluid may escape from one end of the cylinder and be admitted to the other end to cause movement of the carrier I8. The exhaust iluid is returned to the reservoir |86 through the return channel 203.

The hydraulic motor |45 is supplied with fluid from a separate pump 204which has a delivery port 205 and an intake port`208. The pump 204 `is a variable delivery non-reversible pump so therein for maintaining a.` predetermined pressure at the port zas, and in that. portion of?V channel 201 which connects the port to the check; valve 2|9, and also in the branch line 2 which leads to port 2|2 ot the tracer valve.

The port 208 of the reversing valve is adapted to be connected by cannelures 2|3 and 2|4 formed Y 'whichl serves to return the iluid to the intake port 206 of the pump 204. In other words, when the pressure port 208 is connected'to port 2|6, port 2|1 is connected to port 22|; and when the port 208 is connected toport 2|1, the port 2|6 is connected to port 220 through the cannelure 2|3. The reversing valve plunger .2| 5 may be shifted by the manually operable handle 223, movable about a pivot 224 and connected bya pin 225 'to the plunger2l5. From the foregoing it will be seen that the pump 204 and the motor |45-2\ are connected together in a substantially closed circuit in that the pump delivers fluid to the motor and the exhaust fluid from the motor is returned directly to the intake port of the pump.

The tracer valve is so constructed that when the same is shifted by the tracerto cause operation of the hydraulic piston |12 that the branch line 2|| is connected to exhaust whereby the pressure at the delivery port 205 of the pump and the connected portion of channel 201 will drop, thereby permitting the plunger 226 of the check valve 2|0 to move in a direction to throttle momentarily the flow to motor |45 and thereby deaccesso crease the rate of rotation of the work during upward or downward adjustment of the carrier |8. This device anticipates the situation that if the tracer engages a shoulder extending longitudinally of the pattern that the tracer valve will be so positioned thata suillcient drop in pressure will occur in channel 201 to cause the check valve plunger 226 to shut off the ilow entirely to motor |45, thereby stopping the same and giving the cutter sumcient time to surmount the shoulder before rotation begins again.

The manner in which the tracer valve bypasses the iluid from channel 2| to cause a drop in pressure therein will now be explained- The tracer valve plunger has a cannelure 221 which is normally positioned opposite port 2|2 and of sufficient width to extend to the edge of port 228. The port 228 is connected by branch 229 to channel 222 and thereby to the intake port 206 of pump. If, now, the tracer valve plunger moves downward, as viewed in Figure 8, port 2|2 will be'connected to port 228, thereby by-passing part of the fluid from pressure pcrt 205 to4 intake port 206 of pump 204 so that'the volumetric delivery to motor |45 is reduced, which decreases the rate of rotation thereof.

- The tracer valve plunger has another cannelure 230 which is connected by interdrilling with the cannelure 221^wherebywhen the plunger is mved upward the cannelure 230 is connected to port 228, thereby again permitting the pressure uid from channel 2|| to be by-passed into channel 229. Attention is invited to the fact that the spool 23|, which separates the cannelure 230 from the cannelure 200, has sulcient overlap on, the upper side of port 20| so that when the tracer valve moves downward to connect port 2|2 with port 228 that the cannelure 230 is not interconnected to the exhaust port 20|.

It will now be seen thatthe tracer valve has one portion which serves as part of the servomotor mechanism for controlling the vertical position of the spindle carrier I8 and that the servomotor mechanism is supplied from a first pump; and has a second portion which serves as `a control for by-passing fluid from a second supply pump which supplies the motor |45 to thereby reduce the vrate of spiral feed movement-of the work relative to the cutter whenever the servomotor mechanism is operated.

As previously stated, the pump 204 is a unidirectional variable delivery pump and a spring 232 is connected to the pendulum 233 of the pump which acts in a direction to decrease the volumetric delivery of the pump. Adjustable means have been provided for limiting the action of the spring and comprises a peculiarly shaped stop member 234 which engages a curved surface 235 formed on the pendulum 233. 'I'he particular shape of the member 234 is shown more particularly in Figures 5 and 6. The member 234 is connected by a clamping'bolt 236 to a control rod 231 which extends upward, as shown in Figures 1 and 2, and passes through a boss 238 formed integral with the bracket |4|. Furthermore, the rod 231 is fixed against longitudinal movement' with respect to the bracket 238 whereby upon upward or downward movement of the spindle carrier I8 the rod v231 will be moved therewith. The upper end of the rod has an operating knob 239 and also has integral there- `with, as more particularly shown in Figure 4, a pointer 240 which is movable upon 'rotation of sol the rod 231 over a graduated plate 24| which has 75 indicated by the dash and dot line in Figure 5,`

and it will be noted from Figure 6 that thev end face 243 is so shaped, that the curved portion 244, which is substantially a semi-circular, is eccentric to the axis 242 whereby rotation of the member 234 in a counter-clockwise direction will force the pendulum 233, indicated in dash and dot lines in Figure 6, in a direction away from the center 242 which will increase the displacement of the variable delivery pump 204 and thereby increase the actual cutting rate; and rotation of member 234 in a clockwise direction will permit the spring 232 to move the pendulum toward the center 242 and decrease the actual cutting rate.' The true relationship of the parts is shown in lFigure 8, from which it will be seen that as the pointer 240 moves in a clockwise direction, that the member 234 in Figure 8 will rotate in a clockwise direction and thereby 'increase the feed rate.

In addition to determine the 4feed rate the member 234 also serves to maintain this feed or cutting rate constant in spite of variations in the diameter of the work and forthat reason the rod 231 was fixed for movement with the carrier I8 so that as the same is caused to move upward by the cone-shaped pattern |43, the rod 231 and member 234 will also move upward, and as they move upward the member 234 is so shaped'longitudinally as to decrease the displacement of the pump and thereby slow down the rate of rotation whereby the cutting rate will remain the same because the diameter of the Work and pattern has increased. In -other words, when the tracer and cutter are in the position shown in Figure 1 and riding' upon substantially the smallest diameter of the work, the pendulum 233 crosses the member 234 at a point where it is held in the position indicated by the dash and dot line 245, which thereby setsv the pump displacement to yield a cutting rate of 3A" a minute for the substantially minimum diameter shown.

It will be noted from Figure 6 that beginning at each point on the semi-circumference 244 the side ,of the member 234 gradually curves outward as the surface progresses upwardly, and thereforeas the member 234 rises and the radial distance to the curved surface decreasesA the pendulum 233 is moved toward the axis 242 by spring 232 to decrease the volumetric displacement of the pump. Therefore, regardless of the-rotatable setting of the member 234 the element of the surface which lies in a vertical plane and passes through the point of contact betwen the surface of the member 234 and the end of the pendulum is so shaped as to maintain a uniform changev in feed rate as the diameter of theA pattern changes. cumferentially extending cam portions which serve as a selector for'the cutting rate and axially extending cam portions which 'maintain that rate Aconstant regardless .of changein the diameter of the pattern. y

After the pattern has been reproducedv the tracer may be lifted out of contact with the pattern by means of the manually rotatable handle 246 xed with shaft 241 which carries at its inner end a crank arm 248 having a roller 249 on'the end thereof, engaging the underside of a periphera1 flange 25o formed integrally lwith the top of the tracer valve. When the. valve is lifted in this mannerthe port |82 is connected to the port 80, which thereby admits uid to the lower end Therefore, the member 234 has cir ofcylinder 'I1I causing upward movement of the carrier I8. This also opens the by-pass of pump 204 to such an extent that when thecheck valve 226 closes, rotation of the motor |45 ceases. This.

makes it possible to shift the gear |62 out of engagement with gear |59 whereby the table may be returned at rapid traverse to a starting position by the -meansheretofore described.

A Valve I, having amanually operable handle 252, has also vbeen provided across pump 204 to short circuit the motor |45 andthereby stop the rotation thereof in spite of any position that the tracer controlled valve may be in.` l

An emergency relief valve 253 has also' been v provided in parallel with the valve 25| whereby in case of emergency, causing excessive pressure tobuild up in channel 201, the same may berelieved through the relief valve without causing damage to the system.

` The pump |84 is also utilized to serve as a booster pump for the vindependent circuit to motor |45, and to this end has a branch line 254 which is connected to a fluid resistance 255 which causes -a drop in pressure to the outlet line 256. 'I'his line is connected by a second fluid resistance 251 to the return channel 203. By properly selecting resistances 255 and 251 al predetermined pressure may be maintained in channel 256 and this channel may be connected by a branch 259 to the return channel 222 of pump 204 whereby the return channel and its pump will always be supercharged at a predetermined pressure.

An additional safety means has been provided in the form of a fluid operable switch 260 connected in one of the electrical mains 260' or 260" after the main Vswitch 26|' which has, a cylinder 26 connected to the output line I 83 of pump |84,

whereby if for Aany reason this pump is not operating, it will be impossible to start the main prime mover 2I of the transmission mechanism, which is supplied with current from these mains. 'Ihis insures that the operator will have the motor 262, which drives pumps |84 and 204, running before it will be possible to start the prime mover 2| A hand wheel 263 may be provided on the end of shaft 2 64 which supports the worm |.41 whereby when the hydraulic motor |45 is stopped it is possible for the operator to manually rotate the work and pattern, and if the gear |62 is interengaged with the gear |59, a relative spiral movement between the tool and work will result.

'Ihe :friction clutch |58 serves as a safety 93 .whilel the hydraulicI power is still operating the motor |45.

For set-up purposes the cutter spindle `may be supported in an adjustable quill 265, having rack teeth 266 cut in the periphery and interengaged by a pinion 261 operated by a handwheel 268 in the usual manner of such devices.

There has thus been provided an improved machine for reproducing three-dimensional objects which is simple in construction, Ieasy to operate and which automatically maintains a substan tially constant Vcutting rate.

1. In a pattern controlled machine tool, the combination ofv a support capable of rectilinear movement, 'means thereon supporting a work blank and a pattern for rotary movement, power operable means for simultaneously effecting said movements in predetermined timed relation, a

said support, and a tracer adapted tofollow the profile of the pattern and operatively connected for automatically governing th'e movement of said cutter, and said power operable means.

2. A pattern controlled machine tool having a rotary support to which a work blank and a pattern may be mounted for rotation, a cutter movable in the plane of the axis, of rotation of the rotary support for shaping the work blank, a power operable motor for effecting rotation of said support and a bodily longitudinal movement thereof, a second power operable motor for moving the cutter, and a tracersupported for movement with the cutter and having means associated.therewith during engagement with the pattern for controlling actuation of said motors in a manner to produce a three-dimensional cutting path.

3. In a pattern controlled machine tool, the combination of a movable support having a cutter and tracer mounted thereon, a reciprocable support having means for rotatably supporting a work blank and a pattern, power means controlled by the tracer while in contact withthe pattern to cause a relative traversing movement between the supports to eiIect a contouring operation, manually operating means for separating the tracer from the pattern and simultaneously effecting a power separation between the cutter and work, and means for returning the reciprocable support to a starting position.

4. In a machine tool having a rotatable work support and a reciprocable tool slide movable toward and from the axis of rotation of the work support, the combination of power operable port and responsive to movement thereof to vary the rate of iiuid flow in said channel and thereby the rate of rotation of the work support.

6. In a machine tool having a rotatable work support and a tool support movable toward and from the axis of the work support, the combination of uid operable means for effecting rota-v tion of the work support'including a variable delverypump, and means responsive to movement of the tool support for varying the volumetric delivery of said pump and thereby the rate of rotation of the work support.

'1. In a machine tool having a. reciprocating 1 support, a rotatable work holder carried thereby,

.and a cutter support movable relative to the work holder, of power operable means for rotating the work holder and reciprocating the firstnamed support in predetermined timed relation support and a cutter support movable toward and from the axis of rotation of the work support, the combination of power operable means for effecting rotation ofthe work support, power operable means for moving the cutter support toward and from the work support during rotation thereof to vary the diameter of the work, a cutting rate determinator having a circumferentially extending cam portion for predetermining the rate of cutting, and additional cam portions lying normal to the plane of said circumferential portion and responsive to movement of the cutter support for varying the rate of rotation of the work support in accordance with movement of the tool support to maintain said predetermined cutting rate constant.

9. In a. machine tool having a rotatable work support and a tool support, the combination of power'operable means for effecting a relative movement of one support toward and from the other, iiuid operable means for effecting rotation of the workA support including a variable delivery pump, a rotatable and axial movable cutting rate determinator, manually operable means for rotating said determinator, means to connect said determinator for axial movement in response to said relative movement between the supports, a circumferentially extending cam portion on the determinator effective upon rotation thereof for diiferently positioning the displacement regulator of the pump and thus selecting a predetermined cutting'rate, and other cam portions on said determinator effective during axial movement thereof for automatically adjusting the displacement of said pump to maintain the rate of cutting constant.

10. In a machine tool having a rotatable work support and a tool support, the combination of power operable means for eil'ecting a relative movement of one support toward and from the other, iiuid operable means for eecting rotation of the work support including a variable delivery pump, a rotatable and axial movable cutting rate determinator, manually operable means for rotating said determinator, means to connect said determinator for axial movement in response to said relative movement between the supports, a circumferentially extending cam portion on the determinator eiective upon rotation thereof for differently positioning the displacement regulator of the pump and thus selecting a predetermined cutting rate, other cam portions on said determinatoreffective during axial movement thereof for automatically adjusting the displacement of said pump to maintain the rate of cutting constant, and means associated with said determinator for indicating the predetermined rate of cutting for each setting thereof.

11. In a pattern controlled machine tool, the combination of a table for supporting a work blank and a pattern, a carrier mounted for relative movement with respect to said table, means,

to support a cutting tool and a tracer on said` carrier, a iuid operable carrier motor having a pair of ports through which uid may be introduced to effect opposite movement Yof the carrier, uid operable means for effecting a relative feeding movement between the table and carrier including a supply line, means controlled by theI tracer while in contact with the pattern for controlling the introduction of fluid to said ports, and additional means controlled by the tracer to by-pass fluid from said supply line when positioned to introduce fluid to said ports.

12. In a pattern controlled machine tool havlil A aoeaseoY ing a work and pattern support andl a. cutter and tracer support, thencombination of separate fluid operable motors for moving said supports,

a pump having intake and delivery ports connected to one of said motors, a servo-control valve A for determining flow to the other motor, means coupling said servo-control valve for actuation by the tracer in response to movement by the pattern, and additional means responsive to movement of the tracer for variably by-passing uid from said pump supply port to exhaust.

1 3. In a pattern controlled machine tool havl ing a work support and a tool support, the combination with means on one of said supports for means controlled by the tracer for opening saidv branch line to exhaust whenever the first-named valve means is positioned to cause admission of fluid to said fluid operable means for the tool slide.

14. In a pattern controlled machine tool having a work support, a cutter support, means for supporting a pattern on one of said sup'- ports, and means for supporting a tracer on the other support, the combination of a first fluid operable motor connected for effecting a vrelative feeding movement between the supports, a

' second uid operable motor for bodily adjusting one. of said supports with respect to the other, a pump connected in a substantially closed Acircuit, to the first motor, a separate source of fluid supply for the second motor, means controlled by the tracer for governing the ow to said second motor, and additional means controlled by the tracer when moved by the pattern to a position causing admission of fluid to said `Vsecond motor to open said closed circuit whereby the I'eeding rate will be reduced during said bodily adjustment.

15. In a pattern controlled machine tool having a reciprocating table, a rotatable head carried by the table having vmeans* for supporting and rotating a work blank and a pattern, a carrier movable toward andfrom the table; a cutter and a tracer supported by said carrier, a fluid operable motor for eilecting simultaneously rov tation of said head and movement of said table in predetezmined timed relation tov effect; a

spiral cutting path, a pump for supplying -i-uid to said motor, a second -fluid operable motor for 16. In a pattern controlled machine tool hav.-l ing a work support and a cutter support and means for supporting a patte' and tracer on the respective supports, of power operable means for effecting a relative feeding. movement bej tween the supports, a. uid operable motor'in- 1,

'cluding a servo-control valve connected. for actuation by the tracer for'adjusting one slide withA respect to the other during said feedingv movement, a pump for' supplying fiuid pressurev tosaid servo-valve, and means for automatically reducing the displacement of said pump when said servo-valve is closed.

17. A pattern controlled' machine tool having a Work support, a tool supportymeans to support a tracer and a pattern on the respective supports, iiuid operable means for effecting a relative feeding movement between the supports including a supply pump, delivery and re- 18. A pattern controlled Amachine tool hav-l ing a work support; a tool support; means for Y supporting -a pattern and a tracer on the respective supports; a fluid operable motor for eecting a relative feeding movement between the supports, a supply line therefor, fluid operable means for effecting reciprocation vof one" of said supports toward and from the other, a tracer controlled valve having a central position for shutting oilflow to said iiuid operable means,

a check valve in the supply line to said motor, a

branch line between said pump and check valve and connected to said tracer control valve, and portions on said tracer controlled valve'v for opening said branch line upon movement from its central position, said check valve being positioned to close when said branch line is opened to thereby insure positive reduction in the volumetric supply to said motor.

19. In a pattern controlled machine tool, the combination with a Work support and a spindle carrier having a tool spindle journaledtherein,

of transmission means including a prime mover and a variable speed transmission for actuating vsaid spindle; fiuid operable means for moving the spindle carrier toward and from the work support, a pump for supplying fluid tosaid fluid operable means, a pair of power means including a. main switch for controlling the prime mover, an auxiliary switch between the main switch and the prime mover, and means responsive to sol uid pressure from said pump for closing said auxiliary switch whereby the spindle can only be rotated if there is uid pressure to supply said fiuidoperable means. I

20. In a pattern controlled machine tool having a. reciprocable table and a slide movable ,in

a plane normal to the' axis of reciprocation of the table, the combination of means on the. table for rotating a work blank and a pattern, a too and a tracerca'rried by said slide, a fluid operabl --device-'for rotating the Work and pattern and reciprocating said table, means to supply uid under pressure to said fluid operable device, a valve for terminating uid iloiv to said device, and a-hand wheel for rotating the work and -reciprocating said table when said flow is terminated. j. v

21. Ina. pattern controlled machine-tool havingv a table, an actuator therefor, a rotatable support carried by the table, a fluid operable motor for rotating said support, transmission means coupling the motor to the table actuator, a cutter and tracersupported in operative engagement with the work and pattern, means controlled by the tracer for governing operation of the motor and thereby effecting a relative feeding movement between the tool and work, an additional power operable means for actuating the table actuator, and a safety clutch between the actuator and motor to prevent rotation of the work by the table actuator when the same is connected to said additional source of power.

22. Means for converting a vertical type milling machine for profiling purposes comprising a rotatable head attachable to the table of said machine and having means for rotating a work piece and a pattern, a tracer head adapted to be attached to the vertical slide of the machine, a uid operable motor in the first-named head for rotating the work and pattern, fluid operable means for reciprocating the vertical slide of the machine, and means controlled by the tracer in response to the pattern for governing the actuation of said motors.

23. In a pattern controlled machine tool havlng a table, an actuator therefor, a rotatable support carried by the table, uid operable means for rotating said support, transmission means coupling the fluid operable means to said actuator, a cutter and tracer supported for operative engagement with the work and pattern, and means controlled by the tracer for governing actuation of said fluid operable means and thereby relative movement between the tool and work whereby a three-dimensional work piece may be produced in a single operation.

24. In a pattern controlled machine tool, the combination of a movable support having a cutter and a tracer mounted thereon, a reciprocable support having means for supporting a work blank and a pattern, power operable means controlled by the tracer while in contact with the pattern to cause movement of each support and thereby determine two dimensions of the work piece, and additional means operated by said power means to eiect an additional relative movement between the supports and simultaneously with the other movements to determine a third dimension of said work piece.

BERNARD SASSEN. 

